Corner-block fastening



March 13, 1945. F. HiRscH 2,371,329

CORNER-BLOCK FASTENING Filed April 3, 1943 2 Sheets-Sheet 1' Jul; 49

March 13, 1945.

F. HIRSCH CORNER-BLOCK FASTENING Fil ed April 3, 194; 2 Sheets-Sheet 2 :6 R 0 mm .1. a b l r P. m H m mm I Patented Mar. 13, 1945 The invention relates to improvements in block fastening and relates more particularly to improvements in means for fastening corner blocks or legsto the frames of tables or of other pieces o furniture I J l i 'One of the principal objects of the invention is to provide a device for detachably fastening legs to theframes of tables or of other piecesof furniture i r Another object is to' provide a device by the use of which tables and other pieces of furniture may be shipped with the legs detached, and speedily assembled at the place of-destination.

, Another object is to provide interchangeability between legs-of frames for tables and for other piecesof furniture.

Anotherobject isto provide a device for fastening corner-blocks that is simple inconstruction and can be produced at lowv cost, t

A further'object is to provide a fasteningdevice for blocks that, with the exception of screw, washer and nut, obviates theuse of metal.

A further object is; to provide a :brace for. use; in fastening corner-blocks the brace beingfirmly u d to theframa A still further objectis to provide a brace for use in fastening corner-block the brace being firmly secured to the frame thereof andproviding a firm connection between the pieces of said frame without the use of glue or other adhesive sub-; stances. I n t i v Y Further. objects and advantages of the invention will be set forth in part in'the followin specification-and in part will be obvious therefrom'without being specifically pointed out, the samevbeing realized and attained as pointed out in the claims hereof.

Heretofore, various forms of metalibraces or brackets have been employed for connectingthe side 'pieces of. a frame for tables, or for other pieces of furniture for fastening the legs to the Wooden braces or brackets have also'been pro-' vided for this purpose'usingscrews to'fasten the" bracket to the side pieces of the frame, or providing rectangular tenons on the bracket glueing the? same into rectangular kerfs in the side'pieces for securing the side pieces with relation to each I other. The use of metal braces, however, does not provide for the shrinkage or expansion, of, the wood, which may take'placeat any timebefore or after the'flnal assembly, due to the useof undried woodor of conditions of storing or shipping much dependability has been placed in the glue which'binds-the brace to the side pieces, frequent- 1y resulting in the breakdown of the construction at the time of final assembly or even some time thereafter. i

The present inventionis intended to "overcome all of the mentioned deficiencies by employing the use of dove-tail tenonsand'grooves for joining c the brace to 'the side'pieces of the frame at an oblique angle and by providing abutment surfaces therebetween, thus creating a positive connection of one side pi'ece'with relation to'the-other and,

together, with relation to the corner-block or leg. With the above and other objects of the inventionin view, the invention consists in the novel construction, arrangement and combination of various devices; elements and parts, as set forth in ,the claims hereof, oneembodiment of the same being illustrated in the accompanying drawings and described in the specification.- I In-the accompanying-drawings,

J Fig. 1 is a perspective for corner-blocks;

.FigrZ is'a' top view of the same; Fig. 3.is.an extended top view of thesame; "Fig; {4 is a sectional view taken along line 4- -4 ofFig.2; p W j Fig.v 5.is a cross section taken along line 5 -5' ofqFi .2;, r Y

Flg 6 l s a perspective view of a portion of a br e; a

Fig 'l is a in the corner-block construction; and

. Fig; 3 isa perspective view of a sidepiece for cornerblocks. I a V n In carrying the invention into effect in 'the embodiment which I have selected for illustration in the accompanying drawings'and for descriptio n'in this specification and referring now: particularly to Fig. l, I provide a brace lllmade of wood or other nonmetallic material having on bothendsdove-tail tenons H and II integrally connected therewith and said brace also having a cylindrical opening l'2 in its center. 'saiddove-i' tail tenons H and "Il" areembedded in dove-tail grooves lilan'dfl-tf of side pieces l4 and |5, re-

spectivelyLadjacentsaid brace I0. The dove-tail grooves l3'and l'3' 'ofthe side pieces l4 and I5 view of a fastening device diagram,.showing the fiow of force have a cross section which substantially corresponds to .the base and the two adjacent oblique sides of a trapezoid (see Fig. 4) and are slantwise extending from the inside toward the inner surfaces 26 and 28' of said ide pieces; said side pieces I! and [5 are of substantially rectangular cross section and are arranged at a right angle with relation to each other. The ends I! and i 8 of said side pieces do not touch each other, however, but provide a space forracorner-block-ior leg 20' to be placed therebetween,in abutment.

A rectangular triangle is thereby provided by the brace Ill, the side pieces I4 and I5, and the corner-block 20 after the assembly of. the con:

struction. A screw 2| carries a thread for Wood tenons H and II into the grooves 13 and I3 until the surface 31 touches the surfaces 28 and 28'. The block 20, carrying the screw 2| in alignment with the opening l2 of the brace I0, is

brought into position between the ends I! and l8 of the side pieces I4 and IS, the thread 23 protruding through and beyond the opening H of the brace 10 being engaged by the nut 25 for holding the corner-block construction together.

Byti'ghtening, the nut-2'5. on the thread 23 of the screw- 21 towards the outer surface of the brace I 0, a tension is created in said screw which,

in turn, is transmitted to the corner-block 22 on one end and a machine screw:- thread 2-3 on its other end and is screwed withits-thread' 22 into the block 20; when the corner-block. con-- struction is assembled, the screw'2l protrudes through the cylindrical opening i2 of the. brace I0 and. is fastened with, relation thereto by means of. anut 25,,thbrace beingprotected, by a. washer 24.

The inner surface 280i said: side. piece i4; forms an acute angle with the groove L3 of. said. side piece 14, said grooveextending inits. longitudinal direction from the'iinside toward thesurface 26 of' said side-piece M. A V'-shapedrecessl'l is pro,-

U of saidsidepiece It, provides an abutment for the inner surface 3]. of. said brace Ill. The-.sur-- face28 and the surfaceprovided by the bases of the dove-tail grooves liaise form a V-shaped' andrectangular recess. The dove-tail tenons of 7 said sidepiece, integral. therewith, extend from said: surface. provided by, the basesgof said dovetail grooves 13. The side piece l5' hasgrooves I53 and a V;-

shaped recess 21 symmetrically arranged torthe corresponding grooves and V-shaped recess of the side piece I4.

The tenons H and H of said brace m are of smaller width than the width of said brace leaving spaces 32 and 32" between the inside 33 and 33', respectively, of said tenons and the inside 3? of said brace (Figs. 5 and 6); thereby an abute ment is provided between the inside 3| of the brace i0 and the surfaces 28 and 28' of the- V- shaped recesses 21' and 21' of the side pieces W and l5, respectively, without that the insides 33 and 33 of said tenons H and H", respectively, take part in the abutment, thus preventing a possible damage to the tenons when the nut is tightened ontothe screw 2|.

The tenons H- and H integral withsaid brace l ilextend therefrom'in the longitudinal directionthereof; and when thte tenons slide into said? grooves l3 and 13 the brace I8 is moving in perpendicular direction to its longitudinal ex-l tension. I g

The operation'of the above describediembodiment'of'my invention is as follows:

"Thebrace 10' is brought witlri'ts. inside 31' into abutment with the surfaces 28 and" 28' of the side pieces i4 and I5, respectively, by sliding the bringingabout pressure thereof against the ends I! and 18 of the side pieces l4 and 45; in Fig. 7

about the pressure ain the side piece 14 and the pressured in the side piece (5. The pressure a in. theside. piece 14 is splitinto two components 11 antic and the pressure (1 in the. side piece I5 is split into two components 6. and f; the components b.- and e. are absorbed by the abutment of. the surface 31 of the brace 10 against the surfaces, 28 and 28. of the sidepieces I4 and i5, and. provide the counterpart to thetension of thescrew Zi. The component pressures candj, bearing; in opposite direction to each other create a tend-- ency to disengage theside pieces, from itsengagemen-twith' the brace Ill. Thesecomponen-t pressureahowever; and. the tendency resultin therefrom are absorbed by the, contact. of the oblique surfaces: of the: grooves 13 and 13",yconstituting the: oblique sides; of the trapezoid cross section thereof, with the corresponding oblique. surfaces; of; thedove-tail tenons H and H", respectively.

The; tenons It and H may beglued into said grooves 13 and 11'; the glue, however, merely. serves: the function of preventing the brace ill from: falling off itsengagement with the si'clepieces- M and i5"; prior to the attachment of the bl'ocl'c 20 onto the side'pieces. For the assembled construction the adhesive quality of the glue is not needed, theconstructionbeing so arranged piecesfrom said brace.- This side componentpressure has received little or no attention. here: tof'ore, resulting in the breakdown of constructions' that'use' rectangular tenons and grooves for connecting the brace to. the side pieces, held" together onlyby friction and adhesive substance;

or heldto'gether by screws resulting in the bend ing or breaking of the screws or splitting of the brace adjacent said screws;

I do not limit myself to the particular details of construction set forth in the foregoing specificationand'illustrated in the accompanying draw'- ings, as the same refer to and setforth'only one embodiment of the invention and it is obvious that the same be modified, within the scope of the. appended claims, without departing fromthe spirit 'andsccpe of the, invention.

Having thus described the invention, what I claim as new and desire to be secured by Letters Patent, is as follows:

1. A comer-block construction comprising, in combination, a corner-block, two side pieces adjacent thereto and substantially perpendicular to each other, each of which having a V -shaped recess and provided on one of the surfaces of said recess with dove-tail tenons forming dove-tail grooves therebetween, said dove-tail tenons being perpendicular to the other surface of said V- shaped recess, a diagonal brace, adapted to be moved in a direction towards said corner-block for abutting said other surface of said recess of each of said side pieces, and provided at each lateral end with dove-tail tenons arranged to engage and coact with said grooves on one 'of the surfaces of said V-shaped recess of each of said side pieces, for providing a positive connection 'between said side pieces, and means parallel to said dove-tail tenons of said recess and secured to said corner-block and with relation to said brace for causing said brace to move-into abutment, and holding the corner-block construction together. I

2. A corner-block construction comprising, in

combination, a corner-block, two side pieces adjacent thereto and substantially perpendicular to each other, each of which having a V-shaped recess and provided with dove-tail tenons forming dove-tail grooves therebetween on one of the surfaces of said V-shaped recess, said dove-tail tenons being perpendicular to the other surface of said y-shaped recess, a diagonal brace, having a hole and adapted to be moved in a direction towards said corner-block for abutting said other surface of said recess of each of said side pieces,

for causing said brace to'move into abutment,

and holding the comer-block construction together. I l I l 3. A corner-block construction comprising, in combination, a corner-block, a pairqof substan tially symmetrical side pieces adjacent thereto and arranged to form a right angle, each of said side pieces having a V-shaped recess and provided with dove-tail tenons forming dove-tail grooves therebetween on one of the surfaces of said recess, said dove-tail tenons being perpendicular to theother surface of said recess, the

eral end arranged to engage and coact with said grooves and tenons respectively of said side pieces, for providing a positive connection between said side pieces, and means parallel to said dove-tail tenons of said recess and secured to said corner-block with relation to said 'brace for mov ing and pressing said brace against said abut-- ting surfaces and, thereby, holding said cornerand provided at each lateral end with dove-tail block construction together. v 4. In a corner-block construction comprising a corner-block, two symmetrical side pieces, a diagonal brace, and a screw connecting said brace with relation to said corner-block, two pairs of dove-tail tenons parallel to. said screw, one pair 1 of which carried by each of said side pieces on one surface of a V-shaped recess thereof, the

other surface of said recess being in alignment with its symmetrical counterpart, and two dovetail tenons each being formed on a lateral end of said brace and arranged to engage and coact with said dove tail tenons of said side pieces for providing a positive connection between said side pieces and permitting a movement of said brace toward said corner-block, said other pair of surfaces in alignment providing an abutment for the side of the brace facing said corner-block, for" limiting its movement toward the same.

FREDERIC' HIRSCH. 

